Yesterday morning NPR’s Andy Carvin took a break from running one of the world’s best Twitter accounts to explain what it’s like to be a living, breathing real-time verification system.

“All of this is more art than science,” he said.

In truth, it sounds equal parts exhilarating and exhausting.

As has been repeatedly detailed in other places, Carvin is the NPR senior strategist who transformed his Twitter feed into a must-read newswire about the changes taking place in the Arab world. Carvin sends hundreds of tweets a day that, taken together, paint a real-time picture of events, opinions, controversies, and rumors relates to events in the Middle East.

There are few established rules or journalistic policies for what he does. Just as Carvin is breaking ground in curation and crowdsourced verification, he is at the same time encountering new ethical conundrums that must be managed, as with everything else, in real-time.

Yet, when following his work on Twitter, Carvin seems in total control of the onslaught of information. Here he is attempting to confirm information reported by media outlets:

Anyone else reporting this yet? RT @andinieffendi: White House confirms Pres Obama has received a message from Colonel Gaddafi - Sky Newsless than a minute ago via TweetDeck Favorite Retweet Reply

Prodding his followers to help him understand the context of a video:

How unusual is this? RT @ahmed: [VIDEO] female teachers protest outside the civil service ministry in Riyadh http://bit.ly/fKZi2I #saudiless than a minute ago via TweetDeck Favorite Retweet Reply

Sharing information while noting its unconfirmed status:

Hearing reports that Abdul Majeed al-Zindani hurt or killed in car accident. Politician, head of Yemen Muslim B’hood. *Not* confirmed.less than a minute ago via TweetDeck Favorite Retweet Reply

Asking his followers to check in on the status of a fellow Twitter user:

Anyone? RT @SuDif: tweeps any news on @JustAmira ? the lack of action on her timeline is really unusual!less than a minute ago via TweetDeck Favorite Retweet Reply

Challenging a report in order to move towards verification:

Source? RT @mohdashoor: Bahrain regime demolishes “Shahrakkan Maternity Hospital” after it accepted injuries from previous clashes.less than a minute ago via Twitter for iPhone Favorite Retweet Reply

Passing along a report from one of his sources on the ground:

My source in Misurata is saying that at least one Gaddafi tank made it into the city center today, fought with snipers. Unclear who won.less than a minute ago via TweetDeck Favorite Retweet Reply

And here he is yesterday, just minutes after we hung up, sharing a point we discussed:

.@arabisin Been thinking a lot that we need to discourage peeps from using words like BREAKING or CONFIRMED unless actually confirmedless than a minute ago via TweetDeck Favorite Retweet Reply

We spoke about how he judges the accuracy and quality of a tweet, and Carvin said that a red flag for him is when non-journalists adopt the language of breaking news.

“Some of the rumors I see floating around seem to be accompanied by the words ‘breaking’ or ‘confirmed’ or ‘urgent’ all in capital letters,” he said. “I think it’s partially because you’ve got people on the ground in the Middle East hearing information and they’ve very excited about getting it, or feel like it needs to be out there as quickly as possible. They start using phrases that reporters use but they are using them in a very different way.”

Craig Silverman is the editor of RegretTheError.com and the author of Regret The Error: How Media Mistakes Pollute the Press and Imperil Free Speech. He is also the editorial director of OpenFile.ca and a columnist for the Toronto Star.